Improvement in sewing-machines



W. R. LANDFEAR. Sewing-Machines. No. 155,193. Patented s t. 2.2, 13 14.

UNITED STATES PATENT QFFICE.

WILLIAM It. LANDFEAR, OF HARTFORD, CONNECTICUT.

IMPROVEMENT IN SEWING- -MACHINES.

Specification forming part of Letters Patent No. 155,193, datedSeptember 22, 1874; application filed January 13, 1874.

To all whom it may concern:

Be it known that 1, WILLIAM R. LAND- FEAR, of Hartford, State ofConnecticut, have invented an Improvementin Sewing-Machines, of whichthe following is a specification:

This invention relates to machines for sewing leather with a singlewaxed thread by means of a hook or hooked needle, which is provided witha cast-off or slide, which covers the hook and prevents it from catchingthe loop of thread which is around the needle when the needle is passingout of the leather; and consists in a new and improved method ofoperating the cast-off.

In the accompanying drawing, Figure 1 is a front elevation of a part ofa sewing-machine containing my improvement. Fig.2 is a similar view, butshowing the moving parts in a different position. Fig. 3 is a sideelevation of the same; and Fig. 4, a section taken in the line a b, Fig.1.

The parts represented may be arranged either above or below the bed ofthe machine, so that the loops may be formed on the upper or under sideof the leather, as desired, but are represented in the drawing as beingabove the leather, so as to draw the loops upward.

A is part of the frame of the machine, in which the shaft B has itsbearings, the crankpin C projecting fromthe head of the shaft. Theneedle-bar Dis fitted to the guides E E so as to move freely up anddown, and is connected with the crank-pin C, from which it receivesmotion, by the link or pitman F'. The hooked needle G is secured to thelower end of the needle-bar. H is the cast-ofl', which is fitted so asto slide freely up anddown in a groove in the needle-bar, the edge ofthe castoif, near its point or lower end, bearin g against that side ofthe needle on which the hook is situated, in the usual manner. A lever,K, is hung by the fulcrum J to the frame, or to a projection from theguide E. To this lever is secured a pin, I, extending through the frontof the needle-bar, and entering a hole or slot in the cast-off near itsupper end, so that when the lever is moved up and down, the cast-ofiwill be moved by it up and down in its groove. The needle-bar isprovided with a vertical slot for the pin I to move freely in.

By the revolution of the shaft in the direction of the arrow, the needleis moved up and down, and is forced into and withdrawn from the leatherP; at the same time the leverK is caused to swing up and down by meansof the pin M, which is secured to the pitman F,

'and which enters the curved slot L in the lever. This slot is so formedthat when the lever is in its lowest position the lower part of theslot, which is straight, is in a perpendicular position, and, therefore,the lever is not moved by the pin M while the pin is below the curve Nin the slot, and it makes no difference with the position of the lever Kand the cast-off H whether the pitman and needle-bar move downward agreater or a less distance. The point of the cast-off is made to passdown just to the surface of the leather, and the necessity forreadjusting the height of the castoff whenever the length of the strokeof the needle is changed in passing from thick to thin material, andvice versa, and which is usually a source of trouble and annoyance whenthe castofi'is moved by means ofthe needle-bar,is entirely obviated bythis peculiar form and construction of the slot L. The arrangement ofthe parts is such that while the needle is rising the pin M arrives atthe curve in the slot L, and therefore begins to raise the lever K whenthe crank-pin C has made about onequarter of a revolution from itslowest point, as shown in Fig. 2. The hook of the needle has now passedto the top of the leather, and has reached. the point of the cast-off,which will now be raised by the lever K, and by the continued revolutionof the crank-pin the needle and cast-off will both rise to their highestposition.

Now, it is necessary that the needle, in descending, should pass downconsiderably in advance of the cast-off, so that the loop of thread,which is at this time in the eye of the needle, may pass freely out andnot be confined in the eye of the needle by the cast-oft, and thus becarried down into the leather.

In order to accomplish'this result, the pin M is placed some distance atone side of the pivot O, by which the link or pitman is connected to theneedle-bar, and it will be observed that while the crank-pin isperforming the upper part of its revolution the top of the pitman isswung from right to left by the crank-pin, and this swinging motioncauses that part of the pitman to which the-pin M is secured to riseconsiderably more than the pivot O, and thus the point of the cast-offis raised higher than the hook of the needle, and will be maintained ata greater height than the hook during the downward motion of the needleand cast-oft, as indicated by the dotted lines in Fig. 2.

When the crank-pin is performing the lower

